Method of turning vegetable asphalt into superior boiler fuel

ABSTRACT

This invention, which involves a method of turning vegetable asphalt into high-quality boiler fuel, belongs to the field of natural asphalt processing technology. It is intended for acid desaponification of vegetable asphalt at 50 to 100° C., then water washing is performed removing impurities and salt; following this, the asphalt is allowed to stand to separate into layers and the aqueous phase is removed. Neutralization to pH=7 to 8 is then performed using alkali and, after another water wash is performed, the asphalt is allowed to stand to separate into layers and the aqueous phase is separated from it. Then the substance obtained thereby is dried yielding the product. Vegetable asphalt that has undergone modification has the advantages of having low viscosity, generating a small amount of ash, having low sulfur content and a low flash point, and of not being prone to coking when it is burned, and the like, and ensures boiler heat efficiency and also prolongs boiler&#39;s useful life and reduces pollution.

(I) TECHNICAL FIELD

This invention, which involves a method of turning vegetable asphalt into high-quality boiler fuel, belongs to the field of natural asphalt processing technology.

(II) BACKGROUND ART

A large amounts of byproduct—vegetable asphalt—is generated in the course of biodiesel and fatty acid production. This kind of asphalt is primarily used in the production of casting adhesive, rubber softening agents, partitioning agents for prefabricated cement, black printing ink, asphalt coating, surface-active carbon, leather adjuvants, boiler fuel, and the like.

However, because vegetable asphalt is highly viscous, generates a large amount of ash, and has a high flash point, the traditional method of using vegetable asphalt as boiler fuel is extremely likely to result in boiler coking thereby reducing boiler heat efficiency, and moreover, at high temperatures, the heavy metals in the ash corrode furnace pipes, seriously reducing boiler's useful life. In this invention, vegetable asphalt is modified; after being modified through special technological methods, vegetable asphalt can serve as boiler fuel with a superior performance.

(III) TECHNICAL CONTENT

1. Purpose of the invention: The purpose of this invention is to provide a method of modifying vegetable asphalt whereby this modified vegetable asphalt can be used as boiler fuel.

2. Technical solution: This invention comprises a method of turning vegetable asphalt into high-quality boiler fuel. Under this method, vegetable asphalt undergoes acid treatment at 50 to 100° C. for 15 to 60 minutes. Then the asphalt obtained thereby is washed in water to remove impurities and salts. Then the asphalt is allowed to stand to separate into layers and the aqueous phase is separated and removed. Using alkali, the asphalt is neutralized to pH=7 to 8 and is then washed in water again. The asphalt is allowed to stand to separate into layers and the aqueous phase is separated and removed. The product obtained thereby is dried, and then finally certain quantities of additives are added to the product that has been obtained.

Wherein the acid used during acid treatment is one of these: hydrochloric acid, nitric acid, and phosphoric acid, or is a mixture of several of them thereof, and the amount of acid added during the said acid treatment process is 0.1 to 5.0% of the mass of the raw material.

The said modified vegetable asphalt is composed of the following raw material ingredients (mass content): vegetable asphalt 80 to 100%, additives 20 to 0%.

3. Beneficial effect: In implementing the above technical solution, this invention first solves the problem of the utilization of the large amount of vegetable asphalt byproduct generated in the course of biodiesel and fatty acid production. Experiment has shown that the traditional method of directly using vegetable asphalt as boiler fuel is extremely likely to lead to boiler coking thereby reducing boiler heat efficiency, and moreover, at high temperatures, the heavy metals in the ash corrode furnace pipes, seriously reducing boiler's useful life.

In this invention, the vegetable asphalt generated in the course of biodiesel production is first modified through acidification and desalination, and then a definite quantity of additives are added to it before it is used as boiler fuel. Vegetable asphalt that has been modified has the advantages of having low viscosity, generating a small amount of ash, having low sulfur content, a low flash point, of not being prone to coking when it is burned, and the like, and therefore ensures boiler heat efficiency and also prolongs boiler's useful life and reduces pollution. By means of this method, it is possible to greatly increase biodiesel and fatty acid production companies' efficiency.

In comparison with the current art, this invention has substantive special features and represents significant improvements in that:

The modification process used in this invention is carried out at room temperature and atmospheric pressure, the technology is simple, and it is easy to carry out, with a work procedure only requiring heating, stirring, washing, drying, and the like. The entire process is easy to control, the cost of modification is low, and the process can be industrialized and applied easily.

The modification agents used in this method are several acids and salts all of which are in common industrial use. Fine chemical industry products that are exorbitantly expensive are not required. Not only are the modification agents easy to acquire, but also they are inexpensive as well.

The waste liquid generated during the modification process is an acidic aqueous solution containing a small amount of acid. After treatment, it can be recycled and reused; it does not cause pollution of the environment.

In this method, by adding a definite amount of specially prepared additives (front cut fraction obtained in the course of biodiesel production) to the vegetable asphalt, the flash point and viscosity of the vegetable asphalt can be noticeably reduced thereby having an ignition-assisting and viscosity reducing effect.

Vegetable asphalt that has been modified has the advantages of having low viscosity, generating a small amount of ash, having low sulfur content, a low flash point, of not being prone to coking when it is burned, and the like advantages, and therefore ensures boiler heat efficiency and also prolongs boiler's useful life and reduces pollution; it is a new environmentally friendly fuel.

(IV) BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is an overview of the method of turning vegetable asphalt into high-quality boiler fuel according to one embodiment of the present invention.

(V) SPECIFIC EMBODIMENTS

Below, specific embodiments of this invention are brought together by way of further explanation. These embodiments may help researchers better understand this invention but in no way limit this invention.

Acid Acid Treatment Treatment Parameter Temperature Time Amount of Amount of Type of Acid Number (Celsius) (minutes) Acid Used (%) Additive (%) Used 1 80 25 0.74 5 Nitric acid 2 70 30 5.0 8 Hydrochloric acid 3 90 40 0.1 20 Phosphoric acid 4 100 15 0.83 0 Phosphoric acid + nitric acid 5 50 60 1.41 4 Hydrochloric acid + phosphoric acid 6 75 45 1.10 6 Hydrochloric acid + nitric acid

The specific operations implemented in the above embodiment are:

Embodiment 1

Take for an example an instance where 1000 kg of vegetable asphalt is input at once. Add 7.4 kg of 98% nitric acid and, keeping the reaction temperature at under 80° C., allow to react for 25 minutes. Then add 1000 kg of water. Stir and wash in the water at 70° C. for 20 minutes. Allow to stand to separate into layers and remove aqueous phase. Draw the asphalt phase on the top layer and, using alkali, neutralize to pH=7 to 8. Add 1000 kg of water, stir and wash in the water at 70° C. for 20 minutes. Allow to stand to separate into layers and remove aqueous phase. Vacuum dry at 80° C. the upper layer of asphalt obtained thereby. After increasing the pressure to atmospheric pressure, add 50 kg of the front cut fraction obtained in the course of biodiesel production to the asphalt obtained thereby, as an additive, and stir until evenly mixed, thereby obtaining modified vegetable asphalt.

Embodiment 2

Take for an example an instance where 1000 kg of vegetable asphalt is input at once. Add 50 kg of 36% hydrochloric acid and, keeping the reaction temperature at under 70° C., allow to react for 30 minutes. Then add 1000 kg of water. Stir and wash in the water at 65° C. for 15 minutes. Allow to stand to separate into layers and remove aqueous phase. Draw the asphalt phase on the top layer and, using alkali, neutralize to pH=7 to 8. Add 1000 kg of water, stir and wash in the water at 65° C. for 15 minutes. Allow to stand to separate into layers and remove aqueous phase. Vacuum dry at 80° C. the product obtained thereby. After increasing the pressure to atmospheric pressure, add 80 kg of the front cut fraction obtained in the course of biodiesel production to the asphalt obtained thereby, as an additive, and stir until evenly mixed, thereby obtaining modified vegetable asphalt.

Embodiment 3

Take for an example an instance where 1000 kg of vegetable asphalt is input at once. Add 1.0 kg of 85% phosphoric acid and, keeping the reaction temperature at under 90° C., allow to react for 40 minutes. Then add 1000 kg of water. Stir and wash in the water at 65° C. for 15 minutes. Allow to stand to separate into layers and remove aqueous phase. Draw the asphalt phase on the top layer and, using alkali, neutralize to pH=7 to 8. Add 1000 kg of water stir and wash in the water at 65° C. for 15 minutes. Allow to stand to separate into layers and remove aqueous phase. Vacuum dry at 80° C. the product obtained thereby. After increasing the pressure to atmospheric pressure, add 200 kg of the front cut fraction obtained in the course of biodiesel production to the asphalt obtained thereby, as an additive, and stir until evenly mixed, thereby obtaining modified vegetable asphalt.

Embodiment 4

Take for an example an instance where 1000 kg of vegetable asphalt is input at once. Add 5.2 kg of 98% nitric acid and 3.1 kg of 85% phosphoric acid and, keeping the reaction temperature at under 100° C., allow to react for 15 minutes. Then add 1000 kg of water. Stir and wash in the water at 65° C. for 15 minutes. Allow to stand to separate into layers and remove aqueous phase. Draw the asphalt phase on the top layer and, using alkali, neutralize to pH=7 to 8. Add 1000 kg of water stir and wash in the water at 65° C. for 15 minutes. Allow to stand to separate into layers and remove aqueous phase. Vacuum dry at 80° C. the product obtained thereby. Thus modified vegetable asphalt is obtained.

Embodiment 5

Take for an example an instance where 1000 kg of vegetable asphalt is input at once. Add 10 kg of 36% hydrochloric acid and 4.1 kg of 85% phosphoric acid and, keeping the reaction temperature at under 50° C., allow to react for 60 minutes. Then add 1000 kg of water. Stir and wash in the water at 65° C. for 15 minutes. Allow to stand to separate into layers and remove aqueous phase. Draw the asphalt phase on the top layer and, using alkali, neutralize to pH=7 to 8. Add 1000 kg of water stir and wash in the water at 65° C. for 15 minutes. Allow to stand to separate into layers and remove aqueous phase. Vacuum dry at 80° C. the product obtained thereby. After increasing the pressure to atmospheric pressure, add 40 kg of the front cut fraction obtained in the course of biodiesel production to the asphalt obtained thereby, as an additive, and stir until evenly mixed, thereby obtaining modified vegetable asphalt.

Embodiment 6

Take for an example an instance where 1000 kg of vegetable asphalt is input at once. Add 5.6 kg of 36% hydrochloric acid and 5.2 kg of 98% phosphoric acid and, keeping the reaction temperature at under 75° C., allow to react for 45 minutes. Then add 1000 kg of water. Stir and wash in the water at 65° C. for 15 minutes. Allow to stand to separate into layers and remove aqueous phase. Draw the asphalt phase on the top layer and, using alkali, neutralize to pH=7 to 8. Add 1000 kg of water stir and wash in the water at 65° C. for 15 minutes. Allow to stand to separate into layers and remove aqueous phase. Vacuum dry at 80° C. the product obtained thereby. After increasing the pressure to atmospheric pressure, add 60 kg of the front cut fraction obtained in the course of biodiesel production to the asphalt obtained thereby, as an additive, and stir until evenly mixed, thereby obtaining modified vegetable asphalt. 

1. A method of turning vegetable asphalt into high-quality boiler fuel, characterized in that this method comprises the following steps: (1) Acidification treatment: inorganic acid is added to vegetable asphalt for degumming and slight cracking. Characterized in that the inorganic acid and vegetable asphalt are charged in a reaction vessel, heated while stirring to a temperature of 50 to 100° C., and allowed to react at a constant temperature for 15 to 60 minutes. (2) The asphalt obtained in step (1) is washed in water, removing impurities and inorganic salts. Characterized in that, during the water wash, the ratio of the volume of water to asphalt is from 0.5:1 to 10:1, the temperature of the water wash is from 50 to 100° C., and the water wash lasts from 1 to 30 minutes. (3) The substance obtained in step (2) is allowed to stand to separate into layers and the aqueous phase is separated from it. (4) Using salt, the upper layer of asphalt obtained in step (3) is neutralized to pH=7 to 8, and then the asphalt obtained thereby is washed in water. During the water wash, the ratio of the volume of water to asphalt is from 0.5:1 to 10:1, the temperature of the water wash is from 50 to 100° C., and the water wash lasts from 1 to 15 minutes. (5) The substance obtained in step (4) is allowed to stand to separate into layers and the aqueous phase is separated from it. (6) The product is obtained by drying the asphalt obtained in step (5).
 2. The method in accordance with claim 1 of turning vegetable asphalt into high-quality boiler fuel, characterized in that, during acid treatment, the acid used is one from among the group consisting of hydrochloric acid, nitric acid, and phosphoric acid, or is a mixture of several thereof.
 3. The method in accordance with claim 1 of turning vegetable asphalt into high-quality boiler fuel, characterized in that, during acid treatment, the quantity of acid added is from 0.1 to 5% of the mass of the raw material.
 4. The method in accordance with any one of claims 1, 2, or 3 of turning vegetable asphalt into high-quality boiler fuel, characterized in that the front cut fraction obtained in the course of biodiesel production is added to the asphalt after the asphalt has been treated, as an additive.
 5. The method in accordance with claim 4 of turning vegetable asphalt into high-quality boiler fuel, characterized in that the amount of additive that is added is from 0 to 20% of the total weight. 